Reality TV's Jon and Kate announce they plan to separate

NEW YORK - Celebrity parents Jon and Kate Gosselin say they plan to separate.

The co-stars of "Jon & Kate Plus 8," who are parents of sextuplets and twins, made their announcement on Monday's episode of the TLC reality series.

The network had promised a major on-air decision from the couple, whose increasingly troubled 10-year marriage has dominated the series in recent weeks as well as fueling a firestorm of tabloid coverage. Published accounts have alleged infidelity by both partners, accusations they both deny.

Meanwhile, their on-screen relationship has been arms-length at best.

"Very swiftly we turned into two different people," Kate said on the fifth-season premiere last month, which attracted nearly 10 million viewers.

She described how she has grown apart from her husband of 10 years, saying, "it's just hard."

Adding to the strain, Pennsylvania's Labor Department has opened an investigation into whether the show's production is complying with state child labor laws. TLC has said it "fully complies" with state laws and regulations.

The Gosselins' announcement raises new questions about the future of "Jon & Kate," which is TLC's most popular series.